ETC ETC Biological & DNA Evidence

Question 1

Which presumptive test is used to detect the presence of seminal fluid at a crime scene?

Accepted Answer

Acid phosphatase test

Answer

Luminol test

Answer

Kastle-Meyer test

Answer

Benzidine test

Question 2

What is the proper technique for collecting a dried bloodstain from a non-porous surface?

Accepted Answer

Moisten a sterile swab with distilled water, collect the stain, air dry the swab completely, and package in paper

Answer

Scrape the stain into a plastic vial and seal immediately

Answer

Use adhesive tape to lift the stain and place on a backing card

Answer

Apply luminol to rehydrate and collect with a cloth swab sealed in plastic

Question 3

What is touch DNA and from what type of evidence can it be collected?

Accepted Answer

DNA from skin cells deposited through touch — collectible from surfaces like doorknobs, weapons, and steering wheels

Answer

DNA collected only from blood and saliva samples

Answer

A laboratory amplification technique for degraded DNA samples

Answer

DNA taken from decomposed remains only

Question 4

Why should biological evidence never be packaged in sealed plastic bags for long-term storage?

Accepted Answer

Moisture trapped inside promotes bacterial growth and mold that degrades DNA

Answer

Plastic generates static electricity that damages DNA

Answer

Plastic bags are not tamper-evident enough for evidence storage

Answer

UV light penetrates plastic and degrades the sample

Question 5

Which body fluid is identified by the presence of p30 (PSA) protein confirmed by immunological testing?

Accepted Answer

Seminal fluid

Answer

Blood

Answer

Saliva

Answer

Urine

Question 6

How should evidence technicians handle sexual assault evidence kits (SAFE kits) after collection?

Accepted Answer

Refrigerate them at 2–8°C and submit promptly to the laboratory maintaining chain of custody

Answer

Store at room temperature in a locked cabinet until court date

Answer

Freeze immediately at -20°C to preserve samples indefinitely

Answer

Leave at room temperature for no more than 24 hours before disposal if not needed